Hydraulic monitor



Aug. 29, 1961 J. A. MISCOVICH HYDRAULIC MONITOR 4 Sheets-Sheet 1 FiledNov. 12, 1958 INVENTOR. JOHN AJWSCOVICH ATTORNEY 1961 J. A. MISCOVICH2,998,199

HYDRAULIC MONITOR Filed Nov. 12, 1958 4 Sheets-Sheet 2 TIE I INVENTOR.

JOHN A. MISCOVIOH ATTORNEY Aug. 29, 1961 Filed Nov. 12, 1958 J. A.MISCOVICH 2,998,199

HYDRAULIC MONITOR 4 Sheets-Sheet 4 FIE: '7

F'IE IEI INVEN TOR.

JOHN A.mscovlcu ATTORNEY 2,998,199 RAULIC MONITOR John A. Miscovich,Fairbanks, Alaska, assignor, by mesne assignments, to John A. Miscovich,Los Angeles, Calif., Paul E. Fillio, Seattle, Wash., and The J. M.Gaunlett Co. Inc, Seattle, Wash., a corporation of Washington Filed Nov.12, 1958, Ser. No. 773,364 9 Claims. (Cl. 239587) The present inventionappertains to hydraulic moni tors of the type used in placer mining andfire fighting and more particularly relates to hydraulic monitorsarranged to utilize the reaction force of liquid discharged therefrom tochange the direction of discharge of said liquid about two angularlyrelated axes.

One object of the present invention is to provide an improved hydraulicmonitor.

Another object is to provide an improved hydraulic monitor arranged toutilize the reaction force of liquid being discharged therefrom forchanging the direction of discharge of the jet by pivoting the nozzleabout both a vertical and a horizontal axis.

Another object is to provide an improved hydraulic monitor arranged toutilize the reaction force of liquid discharged therefrom to swing thenozzle simultaneously about two angularly related axes or independentlyabout either axis.

'Another object is to provide an improved hydraulic monitor arranged toutilize the nozzle reaction force to swing the nozzle and also arrangedto shift the line along which the nozzle reaction force acts so that itintersects the pivot axes of the nozzle at their point of intersection,and thus to prevent the nozzle reaction from exerting any turning momentupon the nozzle.

Another object is to provide an eccentric swivel joint adaptable for useeither in a hydraulic monitor for achieving the herein stated objects oras an eccentric swivel joint to rotatably interconnect pipe sectionshaving axes which are offset from but are in parallel relation to eachother.

These and other objects and advantages of the present invention willbecome apparent from the following description and the accompanyingdrawings, in which:

FIG. 1 is a perspective of the hydraulic monitor of the presentinvention.

FIG. 2 is a partly broken away enlarged rear elevation of the monitor ofFIG. 1 with the discharge nozzle directly horizontally.

FIG. 3 is a side elevation of the apparatus of FIG. 2.

FIG. 4 is a plan of the apparatus of FIGS. 2 and 3.

FIG. 5 is an enlarged axial section taken along lines 5-5 of FIG. 4,showing the eccentric swivel joint that forms a part of the monitor ofFIGS. 1-4.

FIG. 6 is an enlarged elevation of a portion of the apparatus shown inFIG. 2, certain parts being broken away.

FIG. 7 is a plan of a modified form of the monitor of the presentinvention.

FIG. 8 is an enlarged axial section of a modified form of the eccentricswivel joint used with the monitor of the present invention.

The hydraulic monitor 9 (FIG. 1) of the present invention is animprovement over that disclosed in the United States patent toMiscovich, No. 2,612,402, dated September 30, 1952. The improved monitor9 is mounted on an upstanding, horizontally disposed, flanged end 10 ofa penstock 11 connected to a pipe line 12 which supplies water underpressure to the monitor 9.

"2,998,199 Patented Aug. 29, 1961.

The monitor 9 comprises a vertical swivel joint 18v (FIGS. 1-4 and 6) ofconventional design, having. a lower, flanged, male section 20 bolted tothe flanged end 10 of the penstock 11, and an upper, female section 22rotatably mounted on the lower section 20 by ball bearings 23 (FIG. 6)for free rotation about a vertical axis' V. A elbow 24 is welded to theupper section 22 of the swivel joint 18 and to the female section 26 ofa horizontal swivel joint 28. The male section 30 of the horizontalswivel joint 28 is free to rotate relatively to the female section 26about a horizontal axis H which. intersects the vertical axis V. A 270elbow 32 is: welded at one end to the rotatable section 30 and ter--minates in a circular discharge end 34 the central axis;

C of which intersects the axes V and H at their point: of intersection.The 90 elbow 24 can be rotated 360 about the vertical axis V, whereasthe 270 elbow 32 can:

be rotated somewhat more than 90 about the hori-- zontal axis H.

The above described parts of the monitor 12 are sub stantially identicalto and operate in the same way as. corresponding parts of the hydraulicmonitor disclosed'l in the herein referred to Miscovich patent. Thepres-' ent improvement resides in the structure which is used? toconnect a liquid discharge nozzle 36 to the end 34 of the 270 elbow 32and the combination thereof with the mounting of the nozzle 36 whichimparts theret0 freedom of movement about one or more axes. Thisconnecting structure is an eccentric, three section swivel pipe joint 40(FIGS. 3, 4 and 5) which is arranged to move the axis N of the nozzle36, along which the reaction force F of the jet discharged from thenozzle 36 acts, in selected positions parallel to but offset from thecentral axis C of the discharge end 34 of the 270 elbow 32. When thenozzle axis N is ofiset from either the vertical axis V or thehorizontal axis H, the nozzlev reaction F applies a torque to therotatable parts of the monitor. This torque is applied about the axisfrom which the axis N is offset, urging the discharge end of the nozzle36 to swing in the direction of such offsetting.

For example, when the nozzle axis N is offset above the horizontal axisH as indicated in FIG. 3, the torque acts about the axis H, urging thedischarge end of the nozzle 36 upwardly, and when the axis N is offsetto one side of the vertical axis, the torque generated by the nozzlereaction F urges the discharge end of the nozzle to swing toward thatsame side. It is to be understood that when the monitor is in normaluse, the nozzle reaction F is of considerable magnitude, and, therefore,ample to cause .3

movement of the nozzle and the parts of the apparatus that are free torotate therewith, to turn in the manner indicated, and thus to alter thedirection of the jet issuing from thenozzle.

The eccentric swivel joint 40 (FIG. 5) comprises a tubular inner swiveljoint section in the form of a sleeve 42 which is rigidly connected atone end to the discharge end 34 of the 270 elbow 32 and is concentrictherewith. A tubular eccentric 44 or intermediate joint section, havinga bore 46 concentric with and of the same diameter as the bore 48 of thesleeve 42, is mounted for rotation on the sleeve 42 by means of ballbearings 50. The ball bearings 50 are arranged in two rows in matingannular grooves 52 and 54 in the outer surface of the sleeve 42 and inthe inner surface of the eccentric 44, respectively. An access opening55 in one side of the eccentric 44 provides means for inserting the ballI bearings 50 into, and for removing them from, the

grooves 52 and 54; and a ball retainer plug 55' screwed 7 into theopening 55 prevents accidental escape of the ball bearings.

3: the eccentric 44 coincides with the axis C of the outer end of "the270 elbow, an outer cylindrical surface 58 of the eccentric 44 iseccentrically disposed relatively to the axis. C .,but is concentricwith. the axis N of the nozzle 36. Thenozzle 36-iswelded to a tubularbell housing 60 in a position which is concentric relative to acounterbore ,62 of the housing60. The counterbore 62 is fitted overhthecylindrical surface. 58 of the eccentric 44 and is m,ounted..forrotationv thereon by means of ball bearings .64 which ridein. annulargrooves 66and 68- in the surface'58 .and in the. counterbore 62,respectively. An access. opening 69, provided with a ball retainer plug69!, is provided for the purpose of inserting the ball bearings 64 into,and of removing them from, the grooves 66 and 68., An annular seal 70 isdisposed betweenthe section. Ahandle 74 is secured to the intermediatesectionti44 for the purposeof rotating the same relatively to, the.sleeve 42. A similar handle 75 is secured to the housing 60 for thepurpose of preventing movement of thesamerelative to the intermediatesection 44 when the latter isrrotated about the inner section 42.

The. eccentricity of the swivel joint 40 causes the nozzle36 to bepositioned so that the nozzle axis N, and

hencetthe reaction force F, are at all times offset from.

either the horizontal axis H or the vertical axis V, or

arekofiset from both of these axes at the same time. Wh'enithe. handle.74 is directed vertically upward or verticallyf downward, the force Fintersects the vertical axis V 3nd,.is offset a maximumdistance from thehorizontal Withthe handle 74 positioned in this way, the foice .F willcause or tend to cause the nozzle 36 of theQmonitor 9 to pivot upward ordownward, respectively, about the horizontal axis H but not about thevertical axis V. Similarly, when the handle 74 is di rected horizontallyto the right or to the left (FIG. 2),

the force F will cause, or tend to cause, pivotal move-' mentofthenozzle 36 about the vertical axis V to the a right or to the left,respectively, but not about the hori- Zontal axis H. When the handle 74is positioned between .the horizontal and the vertical positions, the-rfo'r'cetF .will be directed so as to pivot or tend to pivot theimonitor9 about both the horizontal axis H and the verticalaxis V at the same.time and toward the side to 'which the handle points.

It,is,.,to.be understood that the single nozzle 36 of the monitor 9disclosed in FIGS. 1, 2 and 3 can be rotated about its axis N without inany way aifecting the operationof .the same. In this particularinstallation, therefore, rotation is not required between the housing.60

(EIG.'-5) and the eccentric intermediate joint section 44' and henceinterconnection permitting relative rotation between these parts of theswivel joint 40 can be eliminatedand the nozzle 36 can be secureddirectly on the joint section 44. However, with the modified form of theinvention shown in FIG. 7, wherein a monitor 76' I having a pair ofnozzles 36a connected together and to thegeccentric swivel joint-40a bya T 77 is disclosed, it is ;desired that these nozzles be maintained atall times iniheir side by side horizontal planar alignment as shownin;-FIG. 7. For use with this monitor 76, therefore, a swivel joint- 40awhich corresponds to the eccentric swivel joint. 40 :(FIG. 5) to theextent that it includes thezrotatable. connection between. the eccentricinterme-- 4 diate section 44 and the outer section 64 must be used. Thehandle 75a can be used to prevent rotation of the nozzles 36a (FIG. 7)about the axis Na between and parallel to both nozzles, which coincideswith the central axis of the stem 78 of the T 77, or, rotationpreventing means such as an arm (not shown) can be used to pivotallyinterconnecta=9O elbow 24a with either the outer jointsection 60a of theswivel joint 40a or the T 77 to prevent rotationof the nozzles.Obviously, the resultant force Fa from the two nozzles 36a acts alongsaid axis Na. Parts of the monitor 76 which correspond to certain onesof the monitor 9 (FIGS. 1, 2, 3 and 4) have been assigned the samenumerals followed by the suflix a.

Another modified form 80 of the eccentric swivel joint of the-inventionis shown in FIG. 8. 80 is intended to be used in a monitor 81 like themoni tor 9 (FIG. 1) except that the joint 80 is used in place of i thejoint'40 (FIG. 5) The joint80 likewise, is a three section joint, and isin many ways similar to the swivel joint- 40. Therefore only thedistinctive features of the swivel joint 80 will be described in detail.Those parts of the ec-- centric swivel joint 80 which are similar toparts of the eccentric swivel joint 40 will be assigned to the samenumerals followed by the sufiix b.

Aninner section 42b (FIG. 8), an intermediate sec tion 44b and an outersection 66b of the eccentric swivel joint 89 are connected to each otherin the same way as are the corresponding parts of the eccentric swiveljoint 40 (FIG. 5). The bore 82 (FIG. 8) of the intermediate section 4412is beveled at 83 at its downstream end 84 to provide a flow passagewhich cooperates with the bore 86 of the'outer joint section 69b whichis also beveled as at 8-8, to allow fluid to pass therethrough withoutbeing unduly restricted. An outer cylindrical surface 58b oftheintermediate section 44b is concentric with an axis E which-is parallelto but offset from the central axis Cb of the inner joint section 42b. Anozzle 36b is secured, as by welding, to the outer joint section 60b insuch a way that the nozzle axis Nb is parallel to but, when the partsare positioned as shown in FIG. 8, is spacedfromthe axis E- a distanceequal to the spacing of the axis E from the central axis Cb of the innersection 60b.--

Handles 74b and 75b are secured to the intermediate section 44b and theouter section 6tlb, respectively, for

the purpose of rotating these sections relatively to each other,.or forholding either jointsection stationary while the other is being rotated.

It can readily be seen that the location of the axis Nb of the nozzle36b relatively to the central axis Cb of the 270 elbow 32b provides themaximum amount of eccentricity when the two handles 74b and 75b extendin When the handles 74b and"- the same radial direction. 75b extend indiametrically opposite directions the-axis of the nozzle Nb coincideswith the central axis Cb, and under these circumstances the-reactionforce Fb of the nozzle 36b intersects the horizontal axis Hb and the--*vertical axis Vb of the monitor 81 of which it is a part at their pointof intersection. Thus the reaction force does not create any torqueabout either pivot axis, and does not have any tendency to swing thenozzle 36 in anydirection.

If it is desired to keep the nozzle from moving horizontally whilemoving it'vertically, the handles 74b and 75b aremoved equal amounts butin opposite directions from their positions shown in FIG. 8. If movementalong w the horizontal axis Hb is desired with no movement about thevertical axis 'Vb, the-handles 74b and 75b must first" be moved to aposition where they extend the same direc-- The handles 74b and 75b arethen rotated equal amounts in opposite direc--' tions to accomplish theabove described horizontal movetion andina horizontal plane.

ment of the nozzle.

In order to assist in preventing erratic pivotal movement of'the monitor9 (FIGS.- 2, 4 and 6) and to'control the rate of pivotal movement of thesame, friction This swivel joint brakes 94 and 95 are provided for thevertical swivel joint 18 and the horizontal swivel joint 28,respectively.

Since both brakes 94 and 95 are identical, the following description ofthe brake 94 associated with the vertical joint 18 will suflice forboth. Although the brakes 94 and 95 will be described only in connectionwith the monitor 9, it is to be understood that similar brakes can beused with the monitor 76 (FIG. 7) and the monitor 81 (FIG. 8).

As best shown in FIG. 6, the brake 94 comprises an annulus 96 welded tothe male section 20 of the swivel joint 18 in a plane which isperpendicular to the axis V of the swivel joint 18. A tubular brakehousing 98 is welded to the female section 22 of the swivel joint 18with its axis parallel to the axis V. One end 100 of the housing 98terminates immediately adjacent a braking surface 102 of the annulus 96.A cylindrical brake shoe 104 of material having a high coefiicient offriction is secured, as by cementing, in a recess 105 formed in aplunger 106 that is slidable in the housing 98. A brake actuator 108 isslidable in a tubular portion 110 of a drive member 112 and the tubularportion 110 is rotatable in, and about the axis of, the housing 98. Thetubular portion 110 is provided with a slot 114 extending in an axialdirection from one end thereof, and the housing 98 is provided with aslanted, or spiral, slot 116 which is angled over the slot 114. A pin118 is rigidly secured to the brake actuator 108 and projects radiallyoutward through the slots 114 and 116. Thus it can be seen that rotationof the drive member 112 and the actuator 108 causes the actuator to moveaxially in the housing 98. A helical compression spring 120 ispositioned with its ends 122 and 124 seated in recesses 126 and 128 inthe plunger 106 and in the brake actuator 108, respectively. Axialmovement of the actuator 108, therefore, causes the spring 120 to forcethe brake shoe 104 against the braking surface 102 with diiferentamounts of resilient pressure.

A control rod 130 havinga radially projecting handle 131 is rigidlysecured to the driving member 112 by a set screw 132 and is journalledin a bracket 134 (FIG. 2) which is welded to the 90 elbow 24 adjacentthe vertical swivel joint 18. A collar 136 is locked on the arm 130'toprevent axial movement of the arm 130. Thus, rotation of the arm 130causes rotation of the driving member 112 (FIG. 6) and the brakeactuator 108 which results in forcing the brake shoe 104 against thebraking surface 102 of the annulus 96.

In order to hold the rod 130 and controlled parts in any one of a numberof optionally selectable positions, a serrated edge 138 of the tubularbrake housing 98 cooperates with a pin 140 axially slidable in a hole142 in the driving member 112. A spring 144 in the hole 142 is disposedbetween a plug 146, threaded in one end of the hole, and the pin 140 tourge the pin 140 into engagement with selected depressions in thescalloped edge 138 with sufficient force to hold the rod 130 in selectedposition until the rod is intentionally pivoted to another position.

The control rod 130 can be moved to force the brake shoe 104 against thebraking surface 102 with sufficient force to prevent motion between theshoe 104 and the annulus 96, or the rod can be adjusted so as to permitrotation of the annulus 96 relative to the shoe 104 but at a limitedrate. It is apparent, therefore, that the brake 94 can be regulated tomaintain complete control of relative pivotal movement of the parts ofthe monitor on opposite sides of swivel joint 18.

The brake 95 (FIG. 2) cooperates with an annulus 150 which is welded tothe 270 elbow 32. The tubular brake housing 98 of the brake 95 is weldedto the portion 26 of the horizontal swivel joint 28. A bracket 152 whichcorresponds to the bracket 134 is welded to the 90 elbow 24 adjacent thehorizontal swivel joint 28, and a control rod 154 corresponds to the rod130 is rotatably mounted inthe bracket 152. The brake 95 operates withrelation to the horizontal axis H in the same way as the brake 94operates with relation to the vertical axis V.

Although a description of the operation of the differ ent parts has beenincluded with the description of the construction and arrangement ofparts, a rsum of the overall operation of the monitor 9 when using theeccentric swivel joint 40 and the operation of the monitor 81 when usingthe eccentric swivel joint will be here included.

If it is desired to swing the monitor 9 (FIG. 2) horizontally about thevertical axis V, but not about the horizontal axis H, the brake is firstlocked by proper manipulation of the control rod 154 to prevent rotationabout the horizontal axis H. The handle 74 is then pivoted to the right(FIG. 2) if it is desired to pivot the monitor to the right or clockwiseas viewed in FIG. 4. If motion of the monitor in the opposite directionis desired the handle 74 is pivoted to the left (FIG. 2). The rate ofpivotal movement about the vertical axis V can be regulated either bycontrolling the amount of horizontal offset of the nozzle axis N fromthe central axis C by proper manipulation of the handle 74, or bycontrolled actuation of the brake 94.

Swinging of the handle first to one side and then to the other side ofthe vertical will cause the nozzle 36 of the monitor 9 to swing back andforth about the vertical axis V, thereby causing the jet discharged fromthe nozzle 36 to swing horizontally back and forth in a sector-shapedpattern. If it is desired to alter the elevation of the sector-shapedpattern, it is necessary only to momentarily release the brake 95 at atime when the handle 74 is positioned in an attitude other thanhorizontal. If the handle 74 is directed upwardly, the discharge end ofthe nozzle 36 will move upwardly and, conversely, if this handle isdirected downwardly, the discharge end of the nozzle 36 will movedownwardly.

Whereas the operation described in the two preceding paragraphs isconcerned with movement of the monitor 9 primarily about the verticalaxis V, it is apparent that similar movements about the horizontal axisH can be accomplished by corresponding manipulation of the brakes 94 and95 and by movement of the handle 74 above and below a horizontal plane.

The overall operation of the eccentric swivel joint 80 (FIG. 8) with themonitor 81 is similar to that described in connection with the eccentricswivel joint 40 (FIG. 2). However, since the swivel joint 80 (FIG. 8)operates about two eccentrieaxes E and Nb, it makes it possible toexercise a control over the amount of eccentricity of the nozzle axis Nbrelative to the central axis Cb, and, therefore, to regulate the moreprecisely the speed at which the monitor will respond to movement of thecontrol handle 74b.

Although each of the eccentric swivel joints 40 (FIG. 5) and 80 (FIG. 8)has been described as a part of a hydraulic monitor if it is to beunderstood that the eccentric swivel joints can be used with otherapparatus. For example, the swivel joints can be used to connect twoparallel but misaligned pipes.

While severalembodiments of the present invention have been shown anddescribed, it will be understood that various changes and modificationscan be made without departing from the spirit of the invention or thescope of the appended claims.

Having thus described the present invention and the manner in which thesame is to be used, what is claimedas new and desired to be protected byLetters Patent is:

1. A hydraulic monitor comprising a liquid discharge nozzle having anaxis along which a nozzle reaction force acts when liquid is dischargedfrom the nozzle, means mounting said nozzle for pivotal movement about apivot axis, an eccentric swivel joint rotatably mounting I said nozzleon said mounting means for rotary movement of-"the nozzle about an axisparallel to said nozzle axisj and intersecting said pivot axis wherebythe line of ac'tibdofthe nozzle reaction canbe shifted from one side ofsaid pivot axis to the other to reverse thjlijrection' oftlie torquegenerated by the nozzle reaction about said pivot'axis, and means forsupplying liquid u nder pressure "to said nozzle: a W i 2'. A hydraulicmonitor comprising a liquid discharge nozzle'having'an axis along whichareaction force acts wheri'liquid is discharged from the nozzle, meansmounting said nozzle for pivotal movement about a pivotiaxis,

anjeccentric swivel joint rotatably mounting said nozzle on saidmounting means for rotary movement of the nozzle about a first axisparallel'to said nozzle axis or about a second axis also parallel tosaid nozzle axisbut spaced from said first axis, said first axisintersecting said pivot axis whereby rotation of the nozzle about saidfirst axis is effective to dispose the nozzle axis optionally on eitherside of the 'pivotaxis' to cause pivotal movement; ofisaid'nozzle"in'selected direetion'about said pivotal axis by the nozzle reaction,said second 'axis being offset froni'said'pivot axis whereby rotation ofthe nozzle about said isec'ondaxis is effective to vary the distancethat the nozzle axis is offset from said first axis and thereby regulatethe magnitude of the torque exerted bythe nozzle reaction about saidpivot axis.

3; A'hydraulic monitor comprising a liquid discharge nozzle having'an'axis along which a reaction force acts wh'enliquid is dischargedfrom the nozzle, means mount ing said nozzle for pivotal movement abouta pivot axis,

an eccentric swivel joint rotatably mounting said nozzle on'saidmounting means for rotary movement of the nozzle about a first axisparallel to said nozzle axis or first axis intersecting said two pivotaxes at their point of intersection, said second axis being coincidentwith said nozzle axis, and means connected to said swivel joint forrotatingsaid nozzle about said first axis to dispose the cylindricalsurface formed about an axis which is in spaced parallel relation withthe axis of said sleeve, said eccentric having a bore concentric withthe bore of said sleeve, a housing journalled on said cylindricalsurface for free rotary movement thereabout and having the other tubularmember secured thereto with its axis coincident with the axis of saidcylindrical surface, and means providing a liquid seal between saidsleeve and said eccentric and between said eccentric and said housing'inall positions of rotary movement therebetween.

7. In a hydraulic monitor, an eccentric swivel joint adjustablyconnecting two tubular members having ce ntral axes, said swivel jointcomprising a sleeve secured to one of said members and having-an axiscoincident with said central axis of said one tubular member, a tubularabout a second axis also'parallel to said nozzle axis but spacedfromsaid first axis, said first axis intersecting said either side of thepivot axis to cause pivotal movement ofsaid nozzle in selected directionabout said pivotaxis by the nozzle reaction, said second axis beingoffsetff'om saidpi'vot axis whereby rotation of the nozzle about saidsecond' 'axis is effective to vary the distance 'that the pivot axiswhereby rotation of the nozzle aboutisaid first axis is effective todispose the nozzle axis optionally on nozzle axis is offset from saidfirst axis and thereby to" regulate the magnitude of' the'torque exertedby the nozzle reaction about said pivot axis, and brake means connectedto said pivotal mounting means and arranged to fco'ntrol the rate ofpivotal movement'of 'saidno'zzle about said pivot axis.

4. A hydraulic monitor comprising a liquid discharge nozzle having anaxis along which a reaction force acts when liquid is discharged fromthe 'nozzlenmeans for supplying liquid under pressure to said nozzle,means mounting said nozzle for pivotal movement about two intersectingpivot axes, an eccentric swivel joint rotatably mounting said nozzle onsaid mounting means for rotary movement'of the nozzle about a first axisand about a second axis both of which are parallel to and spaced fromeach other, said first axis intersecting said two pivot axes at theirpoint of intersection, said second axis being coincident with saidnozzle axis, and means connected to said swi vel joint for rotating-saidnozzle about said first axis to dispose the nozzle with the line'ofaction of the nozzle reaction in position fo r the nozzle reaction toapply a turning moment to said nozzle about one of said intersectingpivot axes.

'5. A hydraulic monitor comprising a 'liquiddischarg'e nozzle having anaxis along which a reaction force acts when'liq'uidis discharged fromthe nozzle, 'm'eans for supplyin'gliquid under pressure 'to said'nozzle,means mounting said nozzle for pivotal movement'ab'outtwo interesectingpivot axes, an eccentric swivel joint rotatably mounting said nozzle onsaid mounting means for rotary movementof thenozzle about a first and asecond axis which are parallel to and spaced from each other, saideccentric mounted for rotation on saidsleeve about the axis thereof andhaving an outer cylindrical surface formed about an axis which is inspaced parallel relation with the central axis of said sleeve, a housingjournalled on said cylindrical surface and having the othertubularmember secured thereto with its axis parallel to the axis of saidcylindrical surface and spaced therefrom a a distance equal to thespacing of the last mentioned axis from the axis of said sleeve, meansfor freely rotating said eccentric and said housing independently ofeach other, while maintaining their axial disposition, and meansproviding a liquid seal between said sleeve and said eccentric andbetween said eccentric and said housing irrespective of the rotationaldispositions thereof.

8i An eccentric swivel joint comprising a sleeve having a bore, atubular eccentric having a bore concentric with said sleeve borejournalled on said sleeve for rotation about an axis coinciding with theaxis of the sleeve and having an outer cylindrical surface eccentricwith respect to said sleeve and said bores, a housing having a sleeveportion journalled on said cylindrical surface, a tubular member securedto said housing concentrically with respect to said cylindrical surfaceand having'a bore eccentric to said bores of the sleeve and theeccentric,

means providing -a liquid tight seal between said sleeve and saidtubular eccentric and between said tubular ec centric and said housing,and means for freely rotating said tubular eccentric and said housingindependently of each other while maintaining their axial dispositionsand said liquid tight seal therebetween, said last named means includingbearings interposed between said sleeve and said tubular eccentric andbetween said cylindrical surface and the sleeve portion of said housing.

9. A hydraulic monitor comprising an eccentric swivel joint including atubular inner section mounted for pivotal movement about twointersecting pivot axes with the axis of said tubular inner sectionintersecting said pivot axes at their point of intersection, a tubularintermediate section mounted for rotary movement about said axis of theinner section, and an outer tubular section mounted on said intermediatesection for rotary movement about an axis'parallel to and spaced fromsaid axis of the inner joint section, a nozzle mounted on said outersection of the swivel joint with the axis of the nozzle parallel to 9 10said axis of the inner joint section and spaced therefrom ReferencesCited in the file of this patent a distance equal to the distancebetween the axis of the inner joint section and the axis of rotation ofthe outer UNITED STATES PATENTS joint section, and means for connectingsaid inner joint 1,304,980 Hirshstem May 27, 1919 section to a source ofliquid under pressure. 5 2,612,402 Miscovich Sept. 30, 1952

